Blender 2.8 View Layers - "Exclude" feature
Old "Render Layers" are now here, in the top right corner:



In the context menu (RMB) in outliner you can set to any collection to be Excluded, masked (now holdout) or hided (now Indirect Only). 



View layer -> Set Exclude is old Exclude function

View layer -> Set Holdout is old Mask function

View layer -> Set Indirect Only is like you Hide layer, but not exclude it.